Cathode ray tube deflection yoke



July 23, 1957 D E. STUBBINS CATHODE RAY TUBE DEFLECTION YOKE Filed March 20, 1953 INVENTOR. DHNIEL E. STUBBINS ATTORNEY United States Patent CATHODE RAY TUBE DEFLECTION YOKE Daniel E. Stubbins, Westmont, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application March 20, 1953, Serial No. 343,732

4 Claims. (Cl. 317200) The present invention relates to a new and improved electromagnetic deflection yoke of the type employed in conjunction with cathode ray tubes in television and the like.

More specifically, this invention relates to a device which is particularly useful in assembling laminated core yokes wherein the core laminations are provided with slots adapted to receive the coil windings.

In the past, the assembling of laminated cores has been fraught with problems of insulating the windings from the cores and at the same time insuring the necessary mechanical rigidity. One scheme resorted to has been that of wrapping the teeth defined by the slots with some suitable insulating material such as glass tape which, while reasonably effective, has produced a rather cumbersome structure. It is, therefore, a primary object of the present invention to provide means for insulating coil windings from the teeth of their associated core member. I A further difficulty encountered in the assembly of such cores according to known techniques has been that of holding together the relatively thin laminations. One known mode of realizing this end is that of coating the several layers with a cement adapted to secure the layers in a unitary manner. This, as will be appreciated, renders the resultant core much thicker than is necessary or desirable. Hence, another object of the invention is that of providing means for securely fastening the several laminations of a deflection yoke core of the slotted type, which securing means serves additionally as an insulating agency.

In general, the present invention contemplates the provision of insulating sleeves of a tough but pliable plastic or plastic coated insulating material, which sleeves are adapted to fit snugly over adjacent teeth of the several laminations. According to one embodiment, the sleeves may extend from the outer ends of the slots to the bases thereof, thus affording an extremely rigid and well insulated core member. a

As will become apparent, the core sleeves of the invention provide a simple yet eifective means for producing an uncluttered and workmanlike core which is capable of being repeated with gross uniformity and high precision in mass production.

Other objects and advantages of the invention will become apparent to those skilled in the art from a study of the following description of the accompanying drawing in which:

Figure 1 is a front elevation of a laminated deflection yoke core provided with the sleeves as above described;

Figure 6 is a sectional view taken generally in the direction of arrow B of Figure 5; and

Figure 7 is a fragmentary sectional view of a core provided with the form of the invention illustrated in Figures 5 and 6.

Referring to the drawings and, particularly to Figure 1 thereof, reference numeral 10 indicates generally a cathode-ray tube deflection yoke which comprises a plurality of laminations 12 of iron or other suitable material, the laminations being slotted as at 14 to provide radially inwardly extending teeth 16. This type of core is described in U. S. Patent 2,155,514, granted April 25, 1939, to W. A. Tolson et al. and assigned to the assignee of the present invention. Also shown in Figure 1 are several other coil windings indicated by reference numeral 18, which windings are passed between the teeth 16 in a manner well known to those skilled in the art.

As stated earlier, the present inventoin provides means for serving the dual purpose of securing together the laminations 12 and insulating the same from the windings 18. This is accomplished by means of sleeves 20 which may be formed of any suitable electrical insulating material, preferably of a tough but slightly pliable plastic or plastic-coated material and are shaped to fit snugly over the protruding teeth 16 formed by the stack of laminations.

Figure 3 illustrates by way of isometric view one of the plastic sleeves 20 which is, as shown, tapered in one direction in the same manner as are the teeth 16. The taper of the teeth and sleeves is, as will be understood, not a necessary aspect of the invention but is mentioned merely by way of completing the description, since cores of this type generally are provided with tapered teeth in order to render the slots parallel-sided. The sleeve 20, as shown perhaps more clearly in Figure 4, is pulled over the tooth formed by the projections of the core laminations and should be of such size with respect to the latter that a snug fit is effeced.

Figure 3 also shows the relationship of one sleeve 20 with respect to one tooth and, particularly, the fact that such sleeve may extend substantially to the base of the slot 14, thus providing for increased mechanical rigidity of the assembly as well as overall electrical insulation between the coil windings 18 and the core teeth 16. By virtue of the plurality of sleeves 20 fitting over the teeth 16, the laminations are held firmly in place with substantially perfect alignment, thus obviating the need for cement between the laminations.

As has also been stated supra the laminated cores of the prior art were insulated from windings associated with them by means of rather cumbersome tapes, wedges and liners. Here, it will be noted, the sleeves themselves fulfill the necessary requirement of insulation, since the coils 18 are effectively maintained out of contact with the sleeve 16.

In use, the sleeves 20 are fitted snugly over the teeth 15 to provide a rigid core. The coils 18 may then be wound and formed in any suitable manner, after which they may be placed in the slots 14, the longest coils going in first and being followed by successively shorter coils, such that each successive coil holds the preceding one in place. In accordance with the invention, moreover, the sleeves, which may be formed of somewhat resilient material, act to hold the coils firmly in place, so that the straight portions 18' of the coils may be properly positioned substantially flush with the extreme inner ends of the teeth 16, as shown in Figure 1. The arrangement of the coils is further illustrated in Fig. 2.

Fig. 5 illustrates another form of the invention in which the sleeve is provided with a shape which renders it particularly suitable for use in yokes requiring that the coil ends be retained near the inner extremity of the Patented July 23, 1957 core teeth. More specifically, it will be noted that the sleeve 20 of Fig. is shaped internally to accommodate the taper of the teeth of the core. The outer surfaces of the sleeve 20, however, do. not follow the taper of the teeth but, rather, diverge therefrom, as. appears more clearly in the sectional. view of. Fig. 6; In the latter figure, it is seen that internalsurfaces 28 are definedby converging planes in order to con-form to the taper, while the. outer surfaces, 30 of sleeve 29' are divergent when viewed. in the same direction.

of sleeve 20.,the edges 32 will abut when the sleeve 29 are inplace over the teeth 16. This aspect is illustrated in Fig. 7 and will be understood asproviding a positive stop or seat forv the coils. By reason of the divergent sides 30, an opening. 34 is provided between adjacent sleeves, which opening. may be. advantageously employed for accommodating coil. ends. and/or splices between adjacent coils in a seat, as described below. In the event that no such openings as 34 are required. or desired in a particular yoke structure, it will be understood that surfaces 30 of the sleeves may be. made parallel to each other, such that adjacent sleeves will abut. throughout their length from edges 32. to the bottomof the slots defined by adjacent teeth. I

Those familiar with. the art of deflection yokes in general should recognize, from the foregoing, the fact that the elimination. of cement improves the efficiency of the yoke by permitting more laminations to be placed in a stack of specified thickness. Furthermore, the gripping action of the sleeves on the coil windings eliminates the need for slot fillers or wedges which were resorted to in the prior art.

Merely by way of completing the description, it may be noted that the splices that connect the edges of adjacent coils in a set, in series, may be inserted into short pieces of insulating tubing or spaghetti, as such material is referred to in the art, and tucked into the unfilled bottoms of the slots 14, thus being held in place and protected.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. An electromagnetic deflection yoke for a cathode ray tube, which yoke comprises: a cylindrical core made up of a plurality of cylindrical sheets of magnetic material, each sheet being slotted to form radial inward extensions which are tapered so that the adjacent edges of adjacent extensions are substantially parallel, said sheets being arranged with their extensions in registry so that the core is formed with a plurality of laminated teeth, each of which is tapered toward the center of the core; a plurality of magnetic windings located in the slots of said core; and a plurality of individual sleeves of insulating material, each such sleeve having an internal contour tapered in conformity with the taper of one of said laminated teeth and of such size asto iit snugly over one of said laminated teeth, said sleeves being the sole means to secure said sheets together and to insulate the laminated tooth with which it is associated from a winding.

By virtue. of the shape.

2. An electromagnetic deflection yoke for a cathode ray tube, which yoke comprises: a cylindrical laminated core made up of a plurality of cylindrical sheets of magnetic material, each sheet being slotted to form radial inward extensions which are tapered so that the adjacent edges of adjacent extensions are substantially parallel, said sheets being arranged with their extensions in registry so that the core is formed with a plurality of laminated teeth, each of which is tapered toward the center of the core; a plurality of magnetic windings located in the siotsof said core; and a plurality of individual sleeves of insulating material, each such sleeve having an internal contour tapered in conformity with the taper of one of said laminated teeth and of such size as to fit snugly over one of'said laminated teeth, thereby to secure said sheets together and to insulate the laminated tooth with which it is associated from a winding, said sleeves being formed with laterally extending portions such that said laterally extending portions of two adjacent sleeves form a seat within the intervening slot of said core for one of said windings.

3. An electromagnetic deflection yoke which comprises a magnetic core of the cylindrical type having a plurality of slots defining substantially radially extending teeth and an individually formed sleeve of electrical insulating material surrounding each of said teeth, each sleeve extending only along the length of its associated tooth and'being provided with a laterally extending portion intermediate its length such that said portions of said sleeves on adjacent teeth are adapted to abut along at least one line.

4. An electromagnetic deflection yoke which comprises: a cylindrical magnetic core made up of a plurality of cylindrical laminations of magnetic material, each having a plurality of radial slots, said laniinations being arranged with their slots in alignment to form a plurality of laminated radial teeth extending inwardly, said teeth being tapered toward the center of said core, a plurality of bare conductors forming magnetic windings located in the slots between said teeth; and a separate sleeve of electrical insulating material surrounding each such tooth and extending only along the length of its associated tooth, said sleeves being the sole agency for insulating said conductors from said core and for holding said laminations together.

References Cited in the file of this patent UNITED STATES PATENTS 2,155,514 Tolson et al Apr. 25, 1939 2,232,812 Studer Feb. 25, 1941 2,422,592 Sigmund et al. June 17, 1947 2,502,185 Thomas Mar. 28, 1950 FOREIGN PATENTS 387,035 Great Britain Feb. 2, 1933 2,473,332 Great Britain June 14,1949 

